1. Field of the Invention
The present invention relates to a clip-on optic assembly, or, supplementary IOL, and more particularly to such an assembly that is capable of being clipped in-situ onto a previously implanted artificial intraocular lens to change the optical characteristics thereof without having to remove the implanted lens from the eye.
2. Description of Related Art
Intraocular lenses have long been used in patients whose vision has deteriorated due to a variety of conditions, including cataracts, myopia, and other diseases. In some instances, the natural lens is removed and an intraocular lens is implanted to provide the light-focusing optic for the eye. In other instances, the natural lens is not removed and the intraocular lens is implanted against the natural lens, cooperating with it to enhance deteriorated vision.
For various reasons, the implanted intraocular lens is not always sufficient to permanently provide desired vision characteristics. The patient""s condition may change over time or as a degenerative disease progresses. It may not have been technologically feasible to manufacture a lens with the desired optical characteristics at the time of implantation. The implanted lens may even contain an undiscovered optical defect that prevents proper focusing of images on the retina, or a lens of improper power may have been erroneously implanted. Thus, it is desirable and frequently necessary to correct the resulting vision deficiency.
While removal and replacement of the implanted lens is usually possible, it is often not practical or desirable. Due to tissue growth around the haptics or other position fixation means used to maintain the already implanted lens in the eye, as well as adhesion of eye tissue to other portions of the implant, especially when the lens has been implanted for an extended period of time, its removal and replacement involves complex surgery and the risk of loss of vision. Regardless, the minimizing of surgical intrusion is always preferable as it represents lower risk to the patient.
To this end, optic assemblies capable of being placed insitu in the eye onto a previously implanted intraocular lens have been developed. U.S. Pat. No. 4,932,971, issued Jun. 12, 1990 to Kelman shows an optic assembly capable of being clipped onto a previously implanted intraocular lens. The assembly is inserted through an incision into the eye, and clip members attached to the lens body of the assembly are manipulated so that they extend over the peripheral edge of the optic of the previously implanted lens, gripping the assembly thereto. The optic assembly may be manufactured with an optical profile that selectively corrects deficiencies of the original implanted lens or provides selected desired vision characteristics.
In the Kelman xe2x80x2971 optic assembly, the clip members extend over portions of the surface of the first, already implanted intraocular lens. This has the effect of the clip members interfering with light passing through the first lens, and may thereby interfere with the final visual image formed on the retina.
Thus, it would be desirable to provide a clip-on optic assembly to furnish patients already having an implanted intraocular lens with improved visual acumen without subjecting them to the risk associated with complex surgery in removing the implanted lens and replacing it with a new one, while minimizing interference of light passing through the implanted lens due to clip members extending over portions of it.
It is an object of the present invention to provide a clip-on optic assembly.
It is another object of the invention to provide a clip-on optic assembly capable of being clipped in-situ onto a previously implanted artificial intraocular lens to change the optical characteristics thereof without removing such implanted lens from the eye.
It is another object of this invention to provide a clip-on optic assembly that minimizes interference, by the clip members, with light passing through an implanted, or primary, intraocular lens when clipped thereon.
It is a further object of this invention to provide a clip-on optic assembly of a construction enabling an associated minimum risk method for insertion of the assembly through an incision into the eye.
The present invention is a clip-on optic assembly. The assembly is capable of being clipped in-situ onto a previously implanted, or primary intraocular lens to change its optical characteristics without having to remove the implanted or primary lens from the eye or having to seat additional haptics in the eye tissue, while minimizing interference by the assembly of light passing through the primary lens.
The optic assembly comprises a supplementary lens body and at least one clip member extending from the supplementary lens body. The clip member has a grip forming a cavity capable of receiving and gripping at least a portion of a haptic or other position fixation means of the primary implanted lens. Desirably, the clip member or members are sufficiently resilient to permit temporary flexing to facilitate insertion of the supplementary assembly through a minimum size incision into the eye.
The lens body of the supplementary lens preferably has a peripheral size corresponding substantially to the peripheral size of the optic of the primary intraocular lens and a posterior surface shaped to substantially correspond to the anterior surface of the optic of the primary intraocular lens for mounting the supplementary lens thereon. The supplementary lens cooperates with the primary intraocular lens for selectively modifying the optical characteristics of the primary intraocular lens. The supplementary lens may have multi-focal characteristics for providing a multi-focal vision system when clipped onto the primary intraocular lens. The supplementary lens may also be shaped to correct an optical defect of an implanted primary lens discovered after implantation or an improper power of an erroneously installed lens.
This invention contemplates a combination of a supplementary optic assembly clipped onto an implanted primary intraocular lens, which includes in-situ attachment of the optic assembly onto a previously implanted intraocular lens. The invention also contemplates a corresponding method of providing the combination by attachment of the supplementary lens assembly to an primary intraocular lens before inserting the combined optic assembly through an incision into the interior of an eye. The attachment is effected by situating the posterior surface of the supplementary lens body against the anterior surface of the primary intraocular lens and then manipulating, e.g., clamping, the clip member onto a haptic or other position fixation means of the primary intraocular lens.
Other objects and advantages of the present invention will become apparent from the specification and accompanying drawings.